Bola Ahmed Tinubu has been declared the winner of Nigeria’s presidential election. Still, Atiku Abubakar of the Peoples Democratic Party, the second-place finisher, and Peter Obi of the Labour Party, the third-place finisher, said they would challenge the result.

Abubakar said he will “explore all of the legal and peaceful options to reclaim our mandate.” Abubakar has campaigned for president of Nigeria six times.

Tinubu, 70, represents the ruling All Progressives Congress Party and won nearly 36.6 percent of the vote total.

Nigeria is African largest economy. The country holds 37,070, 000,000 barrels of proven oil reserves, according to information issued in 2016.

The country covers an area of 923,769 square kilometers and has a population of over 218.65 million.

Tinubu, former governor of Lagos State, was declared the winner Wednesday of Africa’s most populous nation and its richest country based on oil revenue.

Tinubu spent his early life in South West Nigeria and later moved to the United States in 1975 to study at Richard J. Daley College in Chicago. He later transferred to Chicago State University, where he earned a degree in accounting. He graduated in 1979.

He returned to Nigeria in the early 1980s. He was employed by Mobil Nigeria as an accountant, rising in the ranks at other companies before entering politics as a Lagos West senatorial candidate in 1992 under the banner of the Social Democrat Party.

He has been accused of drug trafficking. Court documents and later reporting on the case showed he was a bagman for two Chicago heroin dealers in the early 1990s.

He is the fifth president since Nigeria returned to Democratic rule. He takes office on May 29.